A longitudinal investigation of sleep hygiene as a mediator linking parental warmth with adolescent sleep

Study Objectives
Parental warmth in adolescence protects sleep in early adulthood, yet the nature, directions, and mechanisms of this association across adolescence are unknown. This study examined parental warmth, adolescent sleep hygiene and sleep outcomes (morning/eveningness, school night sleep duration, and daytime sleepiness) across five annual waves, spanning four years, using a cross-lagged panel design.

Methods
Adolescents and one primary caregiver (96% mothers) completed questionnaires assessing parental warmth (child- and parent-report) and adolescent sleep hygiene and sleep (child-report), across five annual waves: Wave 1 (N = 531, Mage = 11.18, SD = 0.56, 51% male), Wave 2 (N = 504, Mage = 12.19, SD = 0.53, 52% male), Wave 3 (N = 478, Mage = 13.19, SD = 0.53, 52% male), Wave 4 (N = 440, Mage = 14.76, SD = 0.47, 51% male), and Wave 5 (N = 422, Mage = 15.75, SD = 0.49, 51% male).

Results
Greater child-reported parental warmth was indirectly associated with better adolescent sleep (greater morningness, longer school night sleep duration, less sleepiness) through healthier sleep hygiene. The inverse was also often observed. Warmth had a direct relationship with sleep duration and sleepiness, independent of sleep hygiene. Parent-reported parental warmth did not predict, nor was predicted by child-reported adolescent sleep.

Conclusions
Parental warmth may protect against developmental changes in adolescent sleep, partially by improving sleep hygiene practices. Similarly, inadequate adolescent sleep may negatively impact parental warmth via deteriorating sleep hygiene. Sleep hygiene emerged as a key mechanism for protecting adolescent sleep and parent-child relationships.